Tests are back from some of the dead native birds found around the Bingara Showground recently and results suggest the animals had been intentionally poisoned with insecticide.

Acting Northern Branch Director of the EPA Brett Nudd is appealing for community assistance, after it was determined the native birds appear to have eaten bread soaked in Fenthion.

The same poison was found to be the cause of death of hundreds of birds near Dubbo around March this year.

Mr Nudd says the department will re-visit the area on Tuesday.

"We're going to conduct a sweep of that entire area on Tuesday, and what we're trying to do through that sweep is to locate any contaminated bread and any more dead birds and make sure that we're cleaning up all that material," he said.

The dead birds included ravens and currawongs.

"Fenthion is the likely cause of death, [as] this insecticide has been found both in the birds and it's also been found in bread at the scene," Mr Nudd said.

"The fact that it's been found in bread at the scene suggests to us that there's people or persons deliberately seeking to poison the birds in that area."

The Bingara community is being encouraged to assist in Tuesday's sweep.